BEIJING , China -LRB- CNN -RRB- -- Consumers in Beijing 's malls and shops are shunning the milk and poultry sections -- for good reasons .

Poultry products , including eggs , may be contaminated with melamine through animal food .

They are shocked and scared by the news headlines : some food produced in China is tainted with melamine .

`` Of course I 'm worried , '' says a woman shopping in Nanxiaojie Market . Stop eating eggs ? `` That 's not possible , '' she tells CNN . `` If there 's a problem with eggs , it should be solved fundamentally . ''

Chinese premier Wen Jiabao says China will take steps to win back consumers .

`` We will use our actions and high quality of our food products to win the trust and confidence of Chinese people and people around the world , '' he told reporters at the end of a two-day summit of Asian and European leaders in Beijing last weekend . Watch more about the tainted food scandal ''

`` Three minister-level officials have resigned and a government investigation is going on . Whoever is responsible must be brought to justice . We need to protect the Made in China brand , '' said Chinese analyst Victor Gao .

But the problem could be more pervasive . The state-run Nanfang Daily published an investigative story saying that adding melamine into animal feed has become an `` open secret . ''

The report said adding melamine into feed started in the aquatic farming industry five years ago , as a way of faking higher protein levels . Learn more about chemical melamine ''

It then spread into other agro-industries such as poultry . Even more shocking is the allegation that the melamine added is from industrial waste material .

CNN contacted the Ministry of Agriculture about the story , but got no immediate response .

Two years ago , reports revealed pet food exported from China to the United States was spiked with melamine and had sickened and killed dogs .

Several weeks ago , the food scandal spread to milk , biscuits and candies . Now , it is tainted eggs . So far , no illnesses or deaths have been linked to eggs .

Tests in Hong Kong last week showed eggs exported by a Chinese company are contaminated with excessive levels of melamine .

In recent days three other brands of eggs have also been found to contain the chemical .

Small wonder egg sales at the Xinfadi , a wholesale market in Beijing , dropped by 10 percent this week , according to the state-run China Daily .

Chinese officials say the source of the problem is melamine , an industrial chemical used to produce plastics and fertilizer . Melamine is high in nitrogen .

Unscrupulous milk suppliers would water down milk and spike it with melamine -- but in amounts that allowed it to still pass quality tests .

Agriculture experts speculate that eggs tainted with melamine may be the result of tainted feed given to hens . That begs the question : if melamine was in the animal feed , will it make into the meat , and into consumers ' bodies ?

Ingesting melamine in large doses over an extended period of time could cause kidney stones and other illnesses , agriculture and health experts say .

But taking in a small amount of melamine poses no such danger . `` If it 's taken over a long period of time , maybe , but if it 's ingested only for short period of time it does not pose harm on animals , '' says He Jiguo , a professor of food science and nutrition at the China Agriculture University .

He says the animals that end up being slaughtered do not live that long and do not actually ingest enough melamine for it to build up in their systems .

The dogs and cats that were sickened in the United States were probably eating treats and meals tainted with melamine over a long period of time , he explains .

Until the situation is resolved , worried grocery shoppers in Beijing say they 'll just have to eat fewer eggs and more bean-products , like soybeans .

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Chinese premier Wen Jiabao says China will try to win back consumers

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Melamine is said to have been added to animal food products

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Report : Adding melamine to feed started in aquatic farming 5 years ago

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Some grocery shoppers say to eat fewer eggs and more bean-products